"So the last deception will be worse than the first" - It would be worse (in their view) for the people to think that He was the Messiah because He had risen from the dead than it would be to believe Him to be the Messiah because of His teachings. They could more easily pervert, contradict, and refute His teachings (so they thought), than to deny His resurrection. It is interesting to observe that the apostles, when the actual resurrection did take place, did not learn for seven weeks what use to make of it! Thus, it is obvious that they could not have planned a pretended resurrection.
Pilate replied to the Jewish leaders by saying - "You have a guard; go your way, make it as secure as you know how" (Matt. 27:65). If the Jews already had a guard of soldiers at their disposal, then there would have been no need to ask Pilate for one. Pilate consents to their request.
"So they went and made the tomb secure, sealing the stone and setting the guard" (Matt. 27:66). In order to seal the tomb, some believe that one or more cords would have been stretched across the stone that covered the opening into the tomb and then attached at each end with clay that could be marked with an official insignia (which could not be duplicated). This would make it impossible for the tomb to be secretly opened and shut after the clay hardened since the special seal would be broken in the process. Also, the seal would be a deterrent to anyone inclined to steal the body since it was a criminal offense to break a Roman seal.
It should be observed that every possible precaution was taken by Jesus' enemies to prevent deception by His disciples. The tomb was cut out of rock which would make it impossible to steal the body except by entering through the door, and the door was secured by a great stone, sealed, and guarded by Roman soldiers! Ironically, the enemies' efforts would end up providing an impressive proof that Jesus really was raised from the dead!